Thermoelectrical timing control



March 19, 1929. a w, ONE 1,706,168

THERMOELECTR I CAL T IMI NCr CONTROL Filed Aug. 15, 1923 InVentor:Bery'arnin .W. Jgg es,

' His Attorny Patented Mar. 19,1929.

UNITED STATES 1,706,168 PATENT OFFICE.

BENJAMIN W. JONES, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC-TRIO COMPANY, A CORPORATION OF NEW YORK..

THERMOELECTRICAL TIMING CONTROL.

' Application filed August 13, 1923. Serial No. 657,253.

This invention relates to an electric circuit control system embodyingan automatic thermo-electrical timing device for controlling thealternate connection of a translating circuit to a supply source and its(lisconnection therefrom at recurring intervals. The invention isparticularly adapted for periodically flashing on and off the electriclamps of an illuminated advertising sign, although the invention is notnecessarily limited in its application to a sign flashing control. 7

One of the objects of my invention is to provide an improved controlarrangement in such a system which is simple in construction, reliableinoperation, and which may be manufactured and installed with minimumexpense; p 7

Another object of my invention is to provide an automatic timing controlfor a translating circuit capable of safely and effectually handlingrelatively large currents and which is positively governed by athermo-electrical timing device of low current interrupting capacity,having time intervals of heating and cooling independent of the currentin the translating circuit, and provided with means for independentlyregulating the time intervals.

The novel features which I believe to be characteristic of my inventionare set forth in the appended claims. My invention itself, however, bothas to its organization and method of, operation will best be understoodby reference to the following description taken in connection with theaccompanying drawing which shows diagrammatically the application of myinvention to sign flashing control. I

As illustrated in the drawing my improved control is embodied in a signflashing system in which the translating circuit includes the lamps 9,which may be arranged in any desired number and manner to form anilluminated sign. The lamps are supplied with current from supply mainslO and 11 which may be the usual lighting power mains.

An electromagnetic switch 12, of the throw-over type, is provided withcooperating'contacts 13 and 14, which are suitably designed to open andclose the circuit of the lamps 9 composing the sign. Movable contact 14.is carried by switch member 15.

which is operable from the open position shown to its closed position inwhich en gagement is made between movable contact 14 and stationarycontact 13. The switch member 15 is pivotally mounted in the stat onarysupport 16 and is biased to the position to which it is last operated bymeans of the over-center device comprising spring 17 which surrounds pin18, one end of which passes through an aperture in the stationarysupport and the other end of which is pivotally connected to switchmember 15. Movable contact 14 is of the follow-up type so designed as tomake and break engagement with stationary contact 13 when switch member15 is passing through the dead center position of tlie'over-centerbiasing device. The. electromagnetic switch 12 is provided with aplunger or armature 19 which is pivotally connected at one end withswitch member 15 and cooperates with two operating windings 20 and 21,the former of which when energized acts upon the armature 19 to move theswitch to closed position and the latter when energized likewise actsupon the armature 19 to move the switch to open position. The actuationof switch 22 to either open or closed position is accomplished by amomentary energization of the properoperating winding.

A thermo-electrical timing device 22 is provided for automaticallyeffecting the alternate energization of the switch operating windings 20and 21 and comprisesa bimetallic thermal responsive element 23 such asis commonly used in thermostats, and a suitable electrical heater 25.The thermal responsive element 23 is fixed at its lower end instationary base member 24 and has its central portion closely surroundedby the electric heater 25. The element 23 carries near its upper end apair of contacts one of which is adapted to engage with the contact 26when the element flexes to the right into its cool position, and theother of which engages contact 27 when the heater circuit is energizedand causes the thermal responsive element to flex to the left into itshot position. Y I

Contacts 26 and 27 are individually adjustable to the right or left asshown in order that the time intervals of heating and cooling of timingdevice 22 ma lated to vary the time on and off of the translatingcircuit. In this. connection it will be understood that the rate ofheating be reguof timing device 22 depends jointl upon the heatingcapacity of coil 25 and t e heat dissipation facilities of the timingdevice, and that the rate of cooling depends primarily upon the heatdissipation alone. The heating capacity of coil 25 is preferably fixedalthough suitable means may be provided for varying the current in thecoil and correspondingly varying the heating capacity, for example, avar able resistance. But the rate of heat dissipation is always afunction of the difference between the temperature of the device andthat of the surrounding medium. Hence, by moving both contacts 26 and 27to the left the thermal element 23 is operated at a higher temperatureand the time of heating of the timing device 22 is increased and thetime of cooling decreased. Adjustment to the right produces the reverseeffect. Furthermore, it will be evident that increasing or decreasingthe gap between contacts 26 and 27 in- .creases or decreases both thetime of heating and cooling. Thus by proper adjustment of contacts 26and 27 the operation of timing device 22 may be varied to give a widerange of time intervals.

The operation of my invention is as follows; \Vith the supply lines 10and 11 energized from a; suitable source and the several controllingelements in the position shown in the drawing the lamps 9 are dark sincethe sign circuit is open at contacts 13 and 141- and the timing device22 is cooling down as the heater circuit, including heating coil 25, islikewise open. Assume that the time required for the timing device tocool has elapsed, and that thermal responsive element 23 has flexed tothe right into engagement with contact 26. A circuit for the closingwinding 20 of switch 12 is thereby completed from the supply conductor11 through the winding 20, contact 26, thermostat 23,ybase 24, lamps 9and heater 25 in parallel circuit to the other supply conductor 10. Thecurrent flowing in this circuit is relatively small'due to theresistance of coil 20 and hence it is not sufficient to light lamps 9.The 'energizaticn of closing- It will be observed that three circuitsare controlled by the operation of switch 12, one being the translatingcircuit including the sign lamps 9 which is completed as fel lows :-fromsupply conductor 11 through a flexible connection to switch member 15,

through contacts 14 and. 13, lamps 9 to the other supply conductor 10,the second being the heater circuit including heater 25 which may betraced as follows: from the supply conductor 11 through a flexibleconnection to switch member 15, through contacts 1 1 and 13, heater 25,to the other supply conductor 10, and the third being the energizingcircuit of winding 20 or 21 depending upon whether switch 12 is operatedto closed or open position respectively.

Upon the operation of switch 12 to closed position, the engagement ofcontacts 13 and let completes the translating circuit to flash lamps 9from the source, short circuits winding 20, and energizes the heater 25which at once begins to heat up timing device 22. As the timing deviceis heated thermal responsive element 23 draws away from stationarycontact 26 and flexes toward station ary contact 27, thereby opening thecircuit of closing coil 20 of switch 12. However, spring 17 continues tomaintain contacts 13 and 14 in firm engagement until the predeterminedtime required for the element 23 to complete its flexure towards contact27 has elapsed. It should be noted that when the element 23 leavesstationary contact 26 no arcing can occur due to the fact that winding20 has been short circuited by the prior engagement of contacts 14 and13. Upon the engagement of element 23 'with stationary contact 27, acircuit for opening coil 21 of switch 12 is completed from the supplyconductor 11 through switch member 15, contacts 13 and 14, base 24,thermostat 23, contact 27, and through winding 21 to the other supplyconductor 10.. The energization of winding 21 causes armature 19 toquickly move switch member 15 past the dead center position into openposition and thereby interrupt the sign circuit and darken the lamps 9.v The operation of switch 12 to open osition also opens the energizingcircuit 0% winding 21 and interrupts the circuit of heater 25 thuspermitting the timing device 22 to cool. As the timing device coolsthermal responsive element 23 leaves stationary contact 27 and againflexes toward stationary contact 26. Again no arcing can occur .upon thedisen gagenient of element 23 from stationary contact 27 since thecircuit of winding 21 has been interrupted by the previous opening ofswitch 12. After a predetermined interval of cooling the engagement ofcontact 26 by thermal member 23 will be eii'cctcd and the cycle ofoperations just described will be repeated contin'uously'andindefinitely.

The periodicity at which the sign is flashed is practically constant andis not affected by variations in the amount of current consumed in thesign since the heater circuit of the thermo-electrical timing element isconnected to receive encrgv from the line independently of thetranslating circuit-including the sign lamps. It will be understood thatsuitable switches for initi ating and terminating the operation of thesign flasher may be placed either in the sup-. ply mainslO and 11 01 inthe conductors leading therefrom and may manual operatlon or operationby a time clock as desired. Also a plurality of my controls may be usedto control different groups of lamps in a sign thus producing a mostattractive illuminating efiect. i

In accordance with the provisions of the patent statutes, Ifhavedescribed the principle of operation of myinvention, together withthe'apparat'us which'I now consider to represent" the best embodimentthereof, but understood sthat the ap- I' desire" to have-it I paratusshown is' only illustrative and tha't the invention can-(becarriedcjoutby other means. -p

hat I- claim as new and. desire tosecure by Letters Patent otthe UnitedStates is 1; A thermo-electrical, timing" control for a translatingcircuit,- comprising 'an electromagnetic switch for,controlling"saidcircuit, said switch havingpnly one circuit-closing."position and only one circuit-opening pos1 tion, andprovided withmechanism iorbi asing said switch to each of said'positions thereto, aftherino electr-ical when operated timing device operablebetweentwocircuit is successively heated and pet-mitt closing positions,for controllin "the succes sive closure and opening of sax switch, and

connections whereby the said itimieng device in accordance with theoperation ;.of, said switch b'etween said circuit-closing -andcircuit-opening' pos tlons. a I

2. :A thermoeelec'trical control for a translatingfcircuit, comprisinganelectromagnetic switch for controlling said, circuit, said switch havingo'nlyone c rcuit clos ng POSltlOH and. vonly one ClI'Clllt-QPEIllIlgcs1vtion, a thermo-electrical timingdevice; laving a heating element aconnected in 'mul'tip'le relation with the .trans1atin circuit f toprovide a predetermined time otoperation of the device between two'circuit closing positions independently 6f the 'valueo f the currentflow in the'ftranslatin circuit,fand connections whereby the said switch-'is"energizedtosuccessively open-{ and close said translating circuitin accordance with the] operation of said timingdevice and; the saidsaid electromagnetic switch is operated'to said circuit-closing positionandpermittedo to cool when said electromagnetic SW'ltClll is operated tosaid circuit-opening position;

3. A" the'rmo-electrical timing control for a translating circuit,comprising an electromagnetic switch, for controlling said circuit, athermo-electrical timing device under the control of said switch andoperable with a time delay between two circuit-closing pobe arranged forto cool position and only one circuit-opening posi-. t1on, a thermalresponsive element having a predetermined time of operation between twocircuit closin'g positions, an electrical heater circuit forjsaidelement arranged to be enering circuit and-said heater circuit'inaccordance with the operat'ion ofsaid timing device between itscircuit-closing positions.

5. A thermo-electricaltiming control for ma netic SWItCh fOI'controlling said circuit, sai SWItClI having only one circuit-closlngpositionland only, one circuit-opening posi-' gized independently "ofthe current in the translat ng circuit, and connections whereby the saidelectromagnetic switch is successive- 1y energized to close andfopensaid translata translating circuit,fcomprising an electrotion, andhaving anjoperating winding for electromagnetlcally operating theswitchto veach position, mechanism forbiasing said switch to each of saidositions upon opera-v ,tion thereto, a thermo-e ectrical timing deviceoperable between two circuit-closing. positionsfor successivelyenergizing said windings and having a heating element connectedm'multlple relation with the translating circuit to render the operationthereof mdependent of'the value ofcu'rrent flow in said ings aresuccessively deenergizedand the 'circuit, and connections wherebysaid-windtiming device is successively heated and permittedi'to cool in.accordance with the op eration-of said electromagneticswitch between's'aid circuit-closing position and said circuit-o ening osition';

- 6. A tiermo-e 'ectrical'timing control for a translating circuit}comprising an electromagnetic switch for'controlling the said cir- 1cuit and having a; closing winding and an timing. device ,is successivelyf l eat(;dwh opening winding, a2thermo-elect'ricaltiming deviceoperable between two circuit-closing positions forjsuccessivelyenergizing said windings, and connections whereby said closing windingis short circuited and the energizing circuit of said opening winding isopened and the timing deviceis successively heated and permitted to coolin accordance with the operation of said electromagnetic switch betweena circuit-closing and a circuit-opening position.

7. A thermo-electrical control for flashing a translating circuit from asource of current, comprising an electromagnetic switch for flashingsaid circuit, said switch having only one circuit-closing position andonly one circuit opening position and said switch having a closing andan opening winding and being provided with mechanism whereby the switchis biased to the position to which it was last operated, athermo-electrical timing device comprising a circuit controlling thermalelement having an independently adjustable time of operation to hot andcool circuit controlling positions respectively, and an electricalheater coil theretor connected in parallel circuit with said translatingcircuit, and connections whereby the thermal element when in its coolposition energizes said switch closing winding in series circuit withthe translating circuit to operate said switch to simultaneously closesaid translating circuit, short circuit said closing winding, andconnect said heater coil to heat said thermal element and when in itshot position energizes said switch opening winding to operate saidswitch to simultaneously open said translating circuit, open theenergizing circuit of said opening winding, and disconnect said heatercoil to permit said thermal element to cool.

In witness whereof, I hereunto hand this 11th day of August, 1923.

BENJAMIN WV. JONES.

set my

